Peruvian sea extends from the shore to the deepest ocean floor for 200 miles. The Peruvian coastline is more than 3000 km long, it contains bays, cliffs, rocky shores, sandy beaches, islands. Besides, peninsulas that harbour kelp forests, macroalgae patches, mussel beds and wetlands, including mangrove at its northern limit.

Two contrasting surface currents converge in the northern Peruvian sea: (1) the warm El Niño Current and (2) the cold Humboldt Current. These currents delimitate the boundary between the Tropical East Pacific and the Warm Temperate Southeastern Pacific provinces, and create an ecotone, well known by replacement of species and a gradient in sea surface temperature and salinity.

The main marine ecosystem of the Peruvian sea is the Humboldt Current system that extends from central Chile (~ 40°S), to northern Peru (~ 4-5°S). It is unusually cool, despite its proximity to the equator, because of the upwelling of cool waters and nutrients to the surface that increases phytoplankton and consequently raises biological productivity, allowing Peruvian sea to produce more fish per unit area than any other place in the world oceans. High primary production and poor ventilation produces an extremely shallow Oxygen Minimum Zone under surface waters which acts as a barrier, concentrating living resources near to the surface.

The Peruvian Register of Marine Species PeRMS aims to compile an updated list of species occurring along the Peruvian jurisdictional waters. It is expected to be used as a source of information for researchers focusing on Peruvian marine biodiversity. PeRMS is managed by Instituto del Mar del Perú - IMARPE (spanish for Peruvian Marine Research Institute), the governmental institution officially in charge of aquatic research at Peru.

Species listed at PeRMS are based on records from bibliographic sources, which currently includes invertebrates, fishes, reptiles, mammals, birds and seaweeds.